Weekly Recap
Friday 12/27/19 - Thursday 1/2/20
This week on As the World Terns:
Like a loved one that comes by during the holidays, powder snow returned to Northwest Montana last week. The visit was bittersweet. When we ventured out to enjoy the wintery conditions, we found that a new weak layer had grinched its way into the mountains. Mixed in with the low-density snow were near-surface facets and surface hoar. Observers found this weak snow on top of firm surfaces like the santa-sized Christmas Eve Crust, stiff windboard and sun crust. While the exact type and distribution of these layers varied, the bottom line remained the same: weak snow on a sliding surface. The trend of cold temps, calm wind, and spotty precipitation with occasional clear skies continued through the weekend. An atmospheric river was set to arrive on New Year’s Eve and was ready to party. However, before we could say bye to 2019, the Year of the Crust delivered one final reprise: the New Year’s Eve Crust. The storm ultimately delivered roughly a foot of snow on top of the Holiday Sandwich with SWE ranging from about 1.5 inches on Big Mountain to over 3 inches in Noisy Basin. Daytime temps during this time were near freezing with moderate to strong gusts of wind. The combination of a storm snow, a weak structure, and increased holiday activity in the backcountry had us expecting fireworks to kick off 2020. Wednesday saw widespread avalanche activity in Northwest Montana including a fatal avalanche near Seeley Lake. Winds calmed and temperatures cooled into Thursday. Our old cast of persistent weak layers were quiet this week (with the exception of a few propagating results). What ever happened to those guys?
